Apple is known for its pioneering innovation and quality products, and an ingenious patent testifies this further. The Cupertino giant has developed a unique alloy, which will invariably use less gold

Apple is known for its pioneering innovation and quality products, and an ingenious patent testifies this further. The Cupertino giant has developed a unique alloy, which will invariably use less gold, but make the smartwatch more durable and scratch resistant. This unique method was designed by Apple to cut costs on the 18 karat gold Apple Watch Edition series, while simultaneously improving durability. A patent application by the company details the unique method in which it manufactures this 18 karat ‘Apple gold’ that has (on a volume basis) less gold than regular 18 karat gold.

There is a lot of complicated material science mixing-of-alloys at play here, but with this method, Apple has managed to invariably cut down on the manufacturing cost of the Apple Watch 18 karat gold variant. To put it simply, this Apple manufactured gold is stronger and more scratch-resistant than ordinary gold. It is built using low-density ceramic particles instead of precious metals. This new gold metal matrix composite contains roughly half the amount of gold than the normal 18 karat gold composite, invariably cutting manufacturing costs for Apple. Dr Drang from Leancrew tries to explain this method.

Apple’s gold is a metal matrix composite, not a standard alloy. Instead of mixing the gold with silver, copper, or other metals to make it harder, Apple is mixing it with low-density ceramic particles. The ceramic makes Apple’s gold harder and more scratch-resistant—which Tim Cook touted during the September announcement—and it also makes it less dense overall.

The karat measure of gold is based on the mass fraction. One hundred grams of 18k gold has 75 grams of gold and 25 grams of other material. If that “other material” is a low-density ceramic, it takes up a bigger volume than if it’s a high-density metal. Because the casing of a watch is made to a particular size (i.e. volume), not to a particular weight, the Watch will have less gold in it than an 18k case made of a conventional alloy.

Intelligent stuff! The patent reveals that one of the inventors was Theodore Waniuk, a materials science Ph.d who previously worked as a senior scientist for Liquidmetal Technologies before joining Apple in early 2012.

Invariably, this also means that the Apple Watch 18k variant will have much less gold (in volume) than other general 18k gold-plated products. Tim Cook failed to mention this during the unveil in September, but then again it’s not something to brag about .